Probabilistic Seismic Hazard Assessment

This data set shows likely shaking intensity in the San Francisco Bay Region in any 50 year period from all possible faults. It is an equivalent risk to a 500 year flood event. A 10% in 50 years probability was chosen as it most closely aligns with current building standards in the California Building Code. This data set is not intended to be site-specific. Rather, it depicts the general risk within neighborhoods and the relative risk from community to community. This data set was developed in conjunction with the United States Geological Survey (USGS) and California Geological Survey (CGS) by determining Probabilistic Seismic Hazard Assessment for Peak Ground Velocity (PGV) for 52,961 points along a grid covering the entire Bay Area, at intervals of 0.05 degrees longitude and 0.05 degrees latitude. PGV was then converted to the Modified Mercalli Intensity (MMI) measure. This analysis incorporates soil conditions which affect the velocity of ground shaking. ----------------------------------------- The Association of Bay Area Governments' Resilience Program makes this data available, along with other hazard data, in an effort to provide a one-stop-shop for local governments to access data for hazard/resilience planning. More information on the program and its work can be accessed from the Resilience Program information page.